Re: [PATCH] nfnetlink_queue: Use hash to speed up finding entries in nfqueue

[Changli Gao <xiaosuo@gmail.com>]

On Fri, Nov 20, 2009 at 9:12 PM, Patrick McHardy <kaber@trash.net> wrote:
> Changli Gao wrote:
>> Use hash to speed up finding entries in nfqueue.
>>
>> If user implements QoS in userland, packet verdict won't be received in order. At this moment, a hash table is faster than a double linked list when finding the corresponding entries in nfqueue.
>>
>> This patch also fixes a potential bug, which will allows more than one entries with the same id are in the same nfqueue in the extreme.
>
> Instead of a double ID in a purely hypothetical case, we'd now
> get an endless loop. This part doesn't make much sense to me,
> please remove it from the patch.
>

It isn't a endless loop, as we limite the queue size.

>> diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c
>> index 7a9dec9..38c7af1 100644
>> --- a/net/netfilter/nfnetlink_queue.c
>> +++ b/net/netfilter/nfnetlink_queue.c
>> @@ -37,6 +37,9 @@
>>  #endif
>>
>>  #define NFQNL_QMAX_DEFAULT 1024
>> +#define NFQNL_QHT_BITS 8
>> +#define NFQNL_QHT_SIZE (1 << NFQNL_QHT_BITS)
>> +#define NFQNL_QHT_MASK (NFQNL_QHT_SIZE - 1)
>
> Have you considered making the size configurable by passing a new
> attribute in the NFQNL_CFG_CMD_BIND cmd message?
>

OK. It's better users can config the size.

-- 
Regards，
Changli Gao(xiaosuo@gmail.com)
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